A MARINER'S GUIDE TO MARINE WEATHER SERVICES
U.S. Department of Commerce
National Oceanic and Atmospheric Administration
National Weather Service
SMALL CRAFT ADVISORY Forecast winds of 18 to 33 knots - Small
Craft Advisories may also be issued for
hazardous sea conditions or lower wind
speeds that may affect small craft
operations.
GALE WARNING: Forecast winds of 34 to 47 knots.
STORM WARNING Forecast winds of 48 knots or greater.
TROPICAL STORM WARNING:Forecast winds of 34 to 63 knots
associated with a tropical storm.
HURRICANE WARNING: Forecast winds of 64 knots or higher
associated with a hurricane.
These advisories and warnings are "headlined" in marine
forecasts. (Details are included elsewhere in this brochure.)
Small Craft Advisories can be issued up to 12 hours and warnings
up to 24 hours prior to onset of adverse conditions.
Introduction
Few people are affected more by weather
than the mariner. An unexpected change
in winds, seas, or visibility can reduce the
efficiency of marine operations and threaten
the very safety of a vessel and its crew. The
National Weather Service (NWS), a part ofthe
National Oceanic and Atmospheric Adminis-
tration (NOAA), provides marine warnings and
forecasts to serve all who sail for livelihood
or recreation. This pamphlet describes those
marine services available from the NWS and
other agencies.
Warning and
Forecast Services
The warning and forecast program is
the core of the NWS's responsibility to
mariners. Warnings and forecasts provide the
mariner with information for planning and deci-
sion making to protect life and property.
The following are the basic marine
products of the NWS. Other information
is contained in issuances such as weather
statements or outlooks that supplement basic
warnings and forecasts.
Oceanic Products
Coastal Marine Warnings
and Forecasts
Designed for variety of mariners staying near
shore. Issued by selected NWS forecast offices.
Issuance Times (by sections of the U.S.)
East Gulf West AK Hawaii
430A 330A 230A 300A 600A
1030A 930A 830A -- Noon
430P 330P 230P 300P 600P
1030P 930P 830P -- Midnight
Note: Table is for local standard times. Issuance times are 1
hour later for those states that switch to daylight savings time.
Content and Format
COASTAL MARINE FORECAST
NATIONAL WEATHER SERVICE NEW YORK NY
530PM EDT MONDAY MAY 4,1992 (ISSUING OFFICE/TIME)
SYNOPSIS-AN INTENSE COLD FRONT IS CURRENTLY MOV-
ING EAST OVER THE FORECAST AREA. A LARGE HIGH OVER
QUEBEC WILL MOVE TO NEW ENGLAND TONIGHT AND
BECOME STATIONARY. (OVERVIEW OF THOSE THINGS
PRODUCING OR IMPACTING WEATHER)
NYZ501-050330-COMMUNICATIONS CODE-EXPIRE TIME)
WATCH HILL, RI TO MANASQUAN INLET, NJ OUT TO 20 NM
530 PM EDT MONDAY MAY 4 1992(FORECAST AREA/ISSU-
ANCE TIME)
...A GALE WARNING IS IN EFFECT... (For more information on
HEADLINES, see below).
.TONIGHT...NORTHWEST WINDS 35 KTS DIMINISHING BY
MORNING. SEAS 12 FEET SUBSIDING BY MORNING. WIDELY
SCATTERED THUNDERSTORMS.
.TUESDAY...NORTHWEST WINDS 5 TO 15 KTS. SEAS 4 FT.
.TUESDAY NIGHT...NORTH WINDS LESS THAN 10 KTS.
SEAS 2 FT. (WINDS, SEA HEIGHTS, AND WEATHER CONDI-
TIONS SIGNIFICANT TO MARINERS WILL BE INCLUDED
IN THIS SECTION SUBDIVIDED INTO TIME PERIODS
EXTENDING OUT TO APPROXIMATELY 36 HOURS.)
HEADLINES are used to focus attention on warnings or other
important events contained within the forecast. Such headlines
highlight, among other things, SMALL CRAFT ADVISORIES,
GALE WARNINGS, STORM WARNINGS, and TROPICAL
STORM OR HURRICANE WARNINGS as needed.
OFFSHORE WARNINGS AND FORECASTS
Effective times are generally the same as those for coastal
forecasts(slightly different in Alaska). These forecasts, issued
by certain NWS offices, are mainly geared to those mariners
operating far off-shore, a day or more from land.
Offices Issuing Offshore Forecasts
Boston...off New England
Washington DC...off Mid-Atlantic
Miami. ..off Southeast US/Caribbean
New Orleans...Gulf of Mexico
Seattle . . .off Washington/Oregon
San Francisco...off California
Honolulu. ..off Hawaii
Anchorage...Beringl Gulf of Alaska
Content and Format
OFFSHORE FORECAST
NATIONAL WEATHER SERVICE SEATTLE WA
930 AM PDT WED JUL 1 1992 (ISSUING OFFICE/TIME)
WASHINGTON AND OREGON WATERS FROM 60 TO 250 NM
OFFSHORE (DESCRIPTION OF FORECAST AREA)
.SYNOPSIS...A WEAK LOW PRES CENTER 275 NM OFF CAPE
FLATTERYWILL DRIFT SOUTHWARD. (BRIEF DESCRIPTION
OF FEATURES AFFECTING THE WEATHER FORECAST)
CAPE FLATTERY TO CAPE LOOKOUT (SPECIFIC AREA/S/
FOR WHICH FORECAST IS ISSUED)
.TODAY...SOUTHWEST WINDS 15 KTS. SEAS 8 FT.
.TONIGHT AND THU...MOSTLY NORTHWEST WINDS 10 KTS.
SEAS 7 FT.
CAPE LOOKOUT TO POINT ST GEORGE
.TODAY...WEST WINDS 20 KTS. SEAS 8 FT.
.TONIGHT AND THU...WEST WINDS 15 KTS. SEAS 7 FT.
(WINDS, SEA HEIGHTS, AND WEATHER CONDITIONS SIG-
NIFICANT TO MARINERS WILL BE INCLUDED IN THIS
SECTION SUBDIVIDED llVl~ TIME PERIODS EXTENDING
OUT TO APPROXIMATELY 36 HOURS. SMALL CRAFT ADVI-
SORIES ARE NOT INCLUDED IN OFFSHORE FORECASTS.)
.OUTLOOK FRI THROUGH SUN...GALES POSSIBLE SATUR-
DAY AHEAD OF DEVELOPING LOW IN THE NORTH PACIFIC .
(DISCUSSION OF EXPECTED OR POSSIBLE WIND CONDI-
TIONS AFFECTING MARINERS WITHIN 3 TO 5 DAYS)
High Seas Warnings and Forecasts
Forecasts issued by certain NWS offices geared to the needs of
the largest ocean going vessels. Emphasis is placed on gale force
or worse conditions.
Issuing Offices - Issuance Times (UTC)
NMC/NHC - WEST ATLANTIC - 0400 1000 1600 2200
NMC/NHC - EAST PACIFIC - 0430 1030 1630 2230
HNL - NORTH PACIFIC - 0500 1100 1700 2300
HNL - SOUTH PACIFIC - 0530 1130 1730 2330
NMC - NATIONAL METEOROLOGICAL CENTER; Wash. DC
NHC - NATIONAL HURRICANE CENTER; Miami, FL
HNL - NWS FORECAST OFFICE; Honolulu, HI
Content and Format
HIGH SEAS FORECAST
NATIONAL WEATHER SERVICE WASHINGTON DC
1600 UTC WED NOV 13 1991 (ISSUING OFFICE/TIME)
NORTH ATLANTIC NORTH OF 32N TO 65N WEST OF 35W
.FORECAST VALID 0000 UTC FRI NOV 15 1991
(FORECAST AREA/VALID TIME[APPROX 36HR FORECASTIng)
WARNINGS. GALE 49N 5 lW 994 MB AT 1200 UTC MOVING ENE
30 KTS. WITHIN 500 NM OF CENTER NE QUADRANT AND
WITHIN 250 NM OF CENTER SE QUADRANT WINDS 35 TO 45
KTS AND SEAS 15 TO 18 FT. ELSEWHERE WITHIN 600 NM
OF CENTER WINDS 20 TO 30 KTS SEAS 8 TO 13 FT. (THIS
SECTION GIVES FORECAST INFORMATION FOR THOSE
PARTS OF THE FORECAST AREA IMPACTED BY GALE,
STORM, OR HURRICANE FORCE WINDS. IT CONTAINS
THE LOCATION [LATITUDE AND LONGITUDE] AND
CENTRAL PRESSURE [IN MILLIBARS] OF THE SYSTEM
CAUSING THE WINDS, THE FORECAST MOVEMENT OF
THAT SYSTEM,AND THE DISTRIBUTION OF WINDSPEEDS
AND SEAS RELATIVE TO THE SYSTEM'S CENTER.)
SYNOPSIS AND FORECAST. AREA OF SOUTHERLY WINDS
20 TO 30 KTS SEAS 7 TO 12 FT DEVELOPING N OF 58N AND
EOF52W.
HIGH 36N 86W 1028 MB AT 1200 UTC MOVING ESE 20 KTS.
HIGH 35N 48W 1027 MB AT 1200 UTC STATIONARY.
WINDS 25 KTS OR LESS SEAS LESS THAN 3 FT IN HIGH
PRESSURE AREAS. (THIS SECTION CONTAINS FORECAST
INFORMATION FOR THOSE PARTS OF THE FORECAST
AREA NOT DESCRIBED IN THE WARNINGS SECTION.)
HURRICANE AND TROPICAL STORM ADVISORIES
Hurricane and Tropical Storm Advisories are issued for the
Atlantic,Pacific, and the Gulf of Mexico regions by the National
Hurricane Center in Miami and the Central Pacific Hurricane
Center, Honolulu. These advisories are issued at least four times
a day; more often when storms approach land.
Content and Format
HURRICANE IWA SPECIAL ADVISORY NUMBER 15
NATIONAL WEATHER SERVICE HONOLULU HI
6PM HST MON NOV22 1982(ADVISORIES FOR EACH STORM
ARE NUMBERED. ADVISORIES ARE ISSUED FOR TROPI-
CAL AND SUBTROPICAL DEPRESSIONS AND STORMS
AND FOR HURRICANES. THE HEADING INCLUDES THE
ISSUING OFFICEI TIME OF ISSUANCE)
...IWA HAS BEEN UPGRADED FROM TROPICAL STORM TO
HURRICANE... (HEADLINE TO HIGHLIGHT STORM)
HURRICANE IWA LOCATED ABOUT 500 MILES SOUTHWEST
OF HONOLULU MAY IMPACT THE ISLANDS DURING THE
NEXT TWO TO THREE DAYS. HIGH SURF ADVISORIES ARE
CURRENTLY IN EFFECT AND SMALL CRAFT SHOULD STAY
IN PORT DUE TO THE INCREASING SOUTHERLY SWELL
DRIVEN BY IWA.
AT 6 PM HST...0400 UTC...THE CENTER OF HURRICANE IWA
WAS ESTIMATED TO BE NEAR 16 NORTH LATITUDE AND 164
WEST LONGITUDE AND WAS MOVING NORTH AT 9MPH.THE
STRONGEST SUSTAINED WINDS NEAR THE CENTER ARE
ESTIMATED AT 80 MPH ...70 KNOTS...WITH GUSTS TO 100
MPH...85 KNOTS. HURRICANE FORCE WINDS...74 MPH OR
MORE...EXTEND 30 MILES OUT FROM THE CENTER. TROPI-
CAL STORM FORCE WINDS...39 MPH...EXTEND 170 MILES
OUT FROM THE CENTER. CENTRAL PRESSURE IS ESTI-
MATED AT 29.18 INCHES...988 MILLIBARS.
HURRICANE IWA IS EXPECTED TO CONTINUE NORTH AT
9 MPH FOR THE NEXT 12 HOURS. SHOULD IWA CHANGE
DIRECTION AND ACCELERATE...APPROPRIATE WATCHES
OR WARNINGS MAY BE POSTED DURING THE NEXT
36 HOURS.
THE NEXT REGULAR ADVISORY ON HURRICANE IWA WILL
BE ISSUED BY THE CENTRAL PACIFIC HURRICANE CENTER
IN HONOLULU AT 11 PM HST. (THESE ADVISORIES PRO-
VIDE INFORMATION REGARDING COASTAL WATCHES
AND WARNINGS IN EFFECT, STORM LOCATION, 12 TO 24
HOUR FORECAST OF MOVEMENT, EXPECTED WINDS
AROUND THE STORM, CENTRAL STORM PRESSURE, AND
STORM TIDE OR STORM SURGE HEIGHTS.PERIODICALLY
A TABLE IS ADDED TO THIS ADVISORY LISTING THE
CHANCES THAT THE STORM WILL PASS WITHIN 65 MILES
OF VARIOUS SITES.)
TSUNAMI WATCHES/WARNINGS
Tsunamis are seismic sea waves caused by disturbances under the
ocean such as earthquakes and land slides. The damaging effects
of a tsunami are felt mainly at or near the coastline due to
large waves lifting normal water levels and pushing inland. A
tsunami may affect areas hundreds or even thousands of miles from
its origin with devastating results. Tsunamis occur mainly in the
Pacific Ocean and Alaskan Gulf regions because of the surrounding
geologically active areas. Tsunami Watch/Warning bulletins are
issued for the Pacific Ocean and surrounding areas by the NWS
based on the magnitude and location of the underwater geological
event. Content and format are generally the same as for Coastal
Flood Watches Warnings.
GREAT LAKES MARINE WARNINGS AND FORECASTS
The NWS office in Cleveland coordinates products and serves as
focal point for dissemination of the Great Lakes marine weather
program. Special products issued by the Cleveland office for the
Great Lakes include:
Great Lakes Synopsis...Issued twice
daily...(02 and 14 UTC) to summarize the posi-
tion and movement of highs, lows, and fronts
expected to affect the Great Lakes during the
36 hour forecast period.
Great Lakes Storm Outlook...Issued when-
ever storm force winds are possible over at
least one of the Great Lakes within the 36-48
hour period after forecast issuance to describe
approaching conditions.
Great Lakes Storm Summary...Issued ev-
ery 6 hours to describe conditions when winds
of 50 knots or greater are occurring on some
part of the Great Lakes and are expected to
prevail for 12 hours or more.
Great Lakes Ice/Freeze-up/Break-up
Outlooks. . .Issued once a day from fall through
spring to make mariners aware of ice condi-
tions on the Great Lakes. (The NWS office in
Buffalo issues these for Lake Ontario and the
St. Lawrence Seaway.)
WIND SPEED/SEA HEIGHT RELATIONSHIPS
WINDS SEA CONDITIONS
0-3 KTS SEA LIKE MIRROR
4-6 KTS RIPPLES, LESS THAN 1 FT
7-10 KTS SMOOTH WAVELETS, 1-2 FT
11-16 KTS SMALL WAVES, 2-4 FT
17-21 KTS MODERATE WAVES, MANY WHITECAPS, 4-8 FT
22-27 KTS LARGE WAVES,SPRAY, 8-13 FT
28-33 KTS HEAPED SEAS, FOAM FROM BREAKING WAVES, 13-20 FT
34-40 KTS HIGH WAVES, FOAM BLOWN IN WELL MARKED STREAKS,
13-20 FT
41-47 KTS SEAS ROLL, SPRAY MAY REDUCE VISIBILITY, 13-20 FT
48-55 KTS VERY HIGH WAVES, WHITE SEAS, OVERHANGING CRESTS
20-30 FT
56-63 KTS EXCEPTIONALLY HIGH WAVES, 30-45 FT
OVER 63 KTS AIR FILLED WITH FOAM,
SEA COMPLETELY WHITE,
OVER 45 FT
THIS CHART IS BASED ON CRITERIA USED BY THE WORLD
METEOROLOGICAL ORGANIZATION. MARINERS SHOULD
REALIZE THAT THESE VALUES ARE REACHED AFTER
WINDS HAVE BLOWN STEADILY OVER A LARGE ARE;A FOR
AN EXTENDED PERIOD OF TIME. ALSO, THE VALUES GIVEN
ARE AVERAGE OBSERVED WAVE HEIGHTS, NOT THE HIGH-
EST THAT MAY BE SEEN FOR A GIVEN WIND SPEED.
NOAA/PA 92056
Great Lakes Nearshore Forecasts
Issued on a seasonal basis from spring through fall by NWS
offices at Duluth, MN, Marquette, MI; Green Bay, Wl; Milwaukee,
WI;Chicago, IL, Grand Rapids, MI; Muskegon, MI; Sault Ste. Marie,
MI;Alpena, Ml, Ann Arbor, Ml; Cleveland, OH; and Buffalo, NY.
Effective/Issuance Times
Issued within an hour after the appropriate open lake forecasts
and are valid for up to 36 hours.
Content and Format
NEARSHORE MARINE FORECAST
NATIONAL WEATHER SERVICE ALPENA Ml
500 PM EDT TUE JUN 19 1990 (ISSUING OFFICE/TIME)
FOR WATERS WITHIN 5 NAUTICAL MILES OF SHORE ON
LAKE HURON (EXTENT OF NEARSHORE FORECAST)
.SYNOPSIS...HIGH PRESSURE IS BUILDING BEHIND COLD
FRONT MOVING EAST TOWARD CANADA (THIS SECTION IS
OPTIONAL IN THIS PRODUCT. IT DESCRIBES THOSE
SYSTEMS CAUSING FORECAST WEATHER CONDITIONS)
MIZ509-200300- COMMUNICATIONS CODE/EXPIRE TIME
LAKE HURON MACKINAW CITY TO ALABASTER
500 PM EDT TUE JUN 19 1990 (LANDMARKS DENOTING
ENDPOINTS AND THE ISSUANCE TIME OF THE FORECAST)
...A GALE WARNING IS IN EFFECT...(HEADLINE USED
AS NEEDED TO HIGHLI GHT IMPORTANT WEATHER CON-
DITIONS. SMALL CRAFT ADVISORIES, GALE WARNINGS
AND STORM WARNINGS ARE INCLUDED USING THE
STANDARD CRITERIA. )
.TONIGHT...NORTHWEST WINDS 35 KNOTS DIMINISHING
BY MORNING.WAVES 5 T0 7 FEET SUBSIDING BY MORNING
SHOWERS ENDING.
.WEDNESDAY AND WEDNESDAY NIGHT...NORTH-
WEST WINDS 10 TO 15 KNOTS. SEAS 1 TO 3 FEET. CLEAR.
(PROVIDE FORECASTS OF WINDS, WAVES, AND WEATHER
CONDITIONS)
Open Lakes Forecasts
Issued by NWS offices in Chicago (Lake Michigan and Lake Supe-
rior), Ann Arbor (Lake Huron and Lake St. Clair), Cleveland (Lake
Ene), and Buffalo (Lake Ontario).
Issuance Times/Periods Covered
Early Morning (3-4 AM)/Today, Tonight, Tomorrow
Late Morning (9-10 AM) This Aft, Tonight, Tomorrow
Late Aft (3-4 PM)/Tonight, Tomorrow, Tomorrow Night
Evening (9-10 PM)/Overnight, Tomorrow, Tomorrow Night
Content and Format
LAKE FORECAST
NATIONAL WEATHER SERVICE CHICAGO IL
955 AM CDT TUE JUN 25 1991 (ISSUING OFFICE/TIME)
LAKE SUPERIOR FORECAST BEYOND 5 NAUTICAL MILES
FROM SHORE (OMITTED DURING WINTER MONTHS)
...A STORM WARNING IS IN EFFECT...(HEADLINE 1NCLUDED
AS NEEDED TO HIGHLIGHT SIGNIFICANT EVENTS.
GALE AND STORM WARNINGS ARE INCLUDED USING
THE STANDARD CRITERIA. SMALL CRAFT ADVISORIES,
HOWEVER, ARE NOT USED IN THIS FORECAST. )
.THIS AFTERNOON...SOUTHWEST WINDS 50 KNOTS. WAVES
16 FEET. THUNDERSTORMS.
.TONIGHT...WEST WINDS 30 KNOTS. WAVES 10 FEET.
.WEDNESDAY. . .NORTHWEST WINDS 10 TO 20 KNOTS. WAVES
1 TO 3 FEET. (THE OPEN LAKES FORECASTS CONTAIN
EXPECTED WIND DIRECTION AND SPEED, WAVE
HEIGHTS, AND SIGNIFICANT WEATHER CONDITIONS.
THEY ALSO INCLUDE INFORMATION REGARDING STRUC-
TURAL ICING AND LAKE ICE.)
MAFOR 2515/
SUPERIOR 12579 14640 12720 THUNDERSTORMS. WAVES 16
FEET. 221416. (MAFOR - A coded version of the Open Lakes
Forecast, intended for shippers, covering the first 24 hours
of the forecast period appended to the narrative.)
Lakeshore Warnings
Lakeshore Warnings are issued for lakeshore flooding that is
occurring or expected within the next 12 hours and poses a threat
to life or property. Like Coastal Flood Warnings, which have
similar content and format, these warnings allow mariners and
others to take actions protective of life and property.
OTHER MARINE PRODUCTS
Special Marine Warnings
The NWS issues Special Marine Warnings for potentially hazardous
over-water events, usually of short duration (up to 2 hours), not
adequately covered by other marine warnings and forecasts. These
events include thunderstorms, waterspouts, squalls, wind shifts,
and other short-lived conditions. Special Marine Warnings are
issued mainly for the coastal waters and the Great Lakes but may
also be issued for offshore areas.
For severe local storms that also include coastal land areas,
Severe Thunderstorm and Tornado Watches and Warnings are used and
include the phrase "...and adjoining coastal waters" to indicate
a threat to mariners.
Content and Format
SPECIAL MARINE WARNING
NATIONAL WEATHER SERVICE MIAMI FL
115 PM EDT SUN JUN 7 1992 (ISSUING OFFICE/TIME
THESE ARE ISSUED AT ANY TIME AS NEEDED)
THE NATIONAL WEATHER SERVICE HAS ISSUED A SPECIAL
MARINE WARNING UNTIL 2 PM FOR THE AREA BETWEEN
KEY BISCAYNE AND KEY LARGO EXTENDING 20 NAUTICAL
MILES OFF SHORE.
AT 110 PM A STRONG THUNDERSTORM 5 NAUTlCAL MILES
OFF OF THE CITY OF KEY LARGO WAS DETECTED BY MIAMI
RADAR. BOATERS REPORT HEAVY RAIN AND WINDS OF 40
KTS FROM THIS STORM. THE STORM IS MOVING TO THE
NORTHEAST AT 20 KTS AND IS SLOWLY WEAKENING.
BOATERS IN THE THREATENED AREA SHOULD SEEK SAFE
HAVEN OR REMAIN CLOSE TO SHORE UNTIL THE STORM
HAS PASSED.(THlS SECTlON GlVES THE AREA AFFECTED,
THE TIME PERIOD, THE CAUSE, AND USER SAFETY IN-
FORMATION FOR THE WARNING)
Local Marine Forecasts
Local marine forecasts are issued in special circumstances to
provide additional information for harbors, channels, and river
entrances where the information in the coastal waters forecasts
is not sufficient. Winds, sea state, significant weather, ocean
currents or abnormal tides, and bar conditions may be included
based on local needs and the availability of observations. The
format and content of this product is similar to that of the
coastal forecast except that the synopsis section is omitted.
DISSEMINATION OF MARINE WEATHER PRODUCTS
Present dissemination of NWS marine products is by a combination
of government and commercial radio facilities broadcasting in
radio,telephone, radiotelegraph, radiofax, and radioteleprinter
modes. The Marine Weather Services (MSC) Charts, described later
in this brochure, list these services for specific segments of the
US coastline, Puerto Rico and the Virgin Islands, and Guam and
the northern Mariana Islands. Radio frequencies and broadcast
times are also available from the US Coast Guard (USCG).
Dissemination:
Coastal Areas/Great Lakes
NOAA Weather Radio (NWR)- The NWS provides mariners
with continuous broadcasts of the latest weather information from
locations throughout the US. These NWR transmissions repeat up-
to-date recorded messages every four to six mimutes. Although not
dedicated to marine, these NWR broadcasts include coastal waters
forecasts with associated advisories and warnings, selected
offshore forecasts, hurricane advisory information, Great Lakes
warnings and forecasts, buoy and coastal observations, and other
relevant marine information. Coastal NWR broadcasts are tailored
to the needs of mariners in the listening area and generally
reach 20 to 40 miles seaward.
In the US,NWR is primarily received on VHF frequencies of
l62.400, 162.475, and 162.500. Many NWR receivers are equipped
with a
device that automatically activates an alarm or turns on the
receiver when warnings are issued. This enables mariners to know
immediately that hazardous weather is expected.
Coast Guard Broadcasts: The USCG broadcasts coastal and
Great Lakes warnings and forecasts over VHF (channel 22) and
other marine frequencies from many locations.
Commercial Radio Broadcasts: Commercial radio stations in
coastal communities receive NWS marine products through weather
wire or news wire services or by NWR. This information is
broadcast to mariners and the general public over AM and FM
frequencies, usually on a scheduled basis. Some commercial radio
stations also broadcast marine information on other high
frequency channels.
Other: Many coastal offices of the NWS provide a telephone record
ing for the public that includes marine information. Some
offices,as listed on relevant MSC charts, provide a dedicated
recording for marine products. In Alaska, radio frequency 4125
KHZ is continuously monitored by seven NWS sites to provide
mariners with the latest weather information.
Dissemination:
Offshore Waters
Voice: Broadcasts of weather information for the off shore waters
are made by USCG and commercial stations. They are made on a
variety of frequencies available from the USCG and are listed on
the relevant MSC charts.
Text: The USCG broadcasts weather information in text form for
conversion by special receivers. This NAVTEX system enables
mariners to receive paper copies of offshore forecasts (also
coastal waters forecasts in some areas). Information on NAVTEX is
available from the USCG.
Dissemination:
High Seas
Voice: High seas information is broadcast by the USCG and certain
commercial radio stations over a variety of frequencies. Also,
time and frequency radio stations WWV and WWVH provide a short,
45 second summary of high seas storm information each hour.
Text: The USCG and certain commercial radio stations currently
broadcast high seas information over several frequencies in coded
form for conversion to text. This radiotelegraph (CW) system is
currently being replaced by a world-wide satellite delivery
system called INMARSAT. That part of INMARSAT handling marine
safety information is operated in the United States by COMSAT
Corporation. This system will provide direct dial telephone,
telex,and other data connections for marine applications. For
more information on INMARSAT, write to:
COMSAT
950 L'Enfant Plaza, SW
Washington, DC 20024
Radiofacsimile
Radiofax transmissions are provided through cooperation with the
USCG and other organizations for broadcast to coastal and
offshore areas as well as most sections of the high seas. These
broadcasts include surface analysis and forecast charts,
significant weather charts, oceanographic charts, and satellite
imagery. (See applicable MSC charts)
MARINE SERVICE CHARTS
MSC charts are available for twelve coastal segments of the conti
nental US and the Great Lakes. MSC charts are also produced for
Alaska, Hawaii, Puerto Rico and the Virgin Islands, and Guam and
the northern Mariana Islands. These are updated periodically to
ensure currency.
MSC charts contain- l) a map of the area including locations of
NWR transmitters, USCG stations, and marine observation sites. 2)
such helpful information as, locations, times, and frequencies of
main broadcasts and 3) NWS contact points.
MSC charts can be purchased from:
National Ocean Service
Distribution Branch (N/CG33)
Riverside, MD 20737
Telephone: 301-436-6990
MSC1 NEW ENGLAND, EASTPORT, ME TO MONTAUK PT.,NY
MSC2 LONG ISLAND, MONTAUK PT., NY TO MANASQUAN INLET, NJ
MSC3 MID-ATLANTIC, MANASQUAN INLET,NJ TO CAPE HATTERAS, NC
MSC4 SOUTH ATLANTIC, CAPE HATTERAS, NC TO SAVANNAH, GA
MSC5 FLORIDA, SAVANNAH, GA TO APALACHICOLA, FL
MSC6 GULF OF MEXICO, APALACHICOLA, FL TO MORGAN CITY, LA
MSC7 TEXAS, MORGAN CITY, LA TO BROWNSVILLE, TX
MSC8 SOUTHERN CALIF., MEXICAN BORDER TO PT.CONCEPTION, CA
MSC9 NORTHERN CALIF., PT. CONCEPTION, CA TO
PT ST GEORGE,CA
MSC10 PACIFIC NORTHWEST, PT. ST. GEORGE, CA TO
CANADIAN BORDER
MSC11 WESTERN GREAT LAKES, LAKE MICHIGAN AND LAKE SUPERIOR
MSC12 EASTERN GREAT LAKES, LAKE ONTARIO, LAKE HURON, AND
LAKE ERIE
MSC13 HAWAII
MSC14 PUERTO RICO AND THE VIRGIN ISLANDS
MSC15 ALASKA
MSC16 GUAM AND THE NORTHERN MARIANA ISLANDS
Weather Rules For Safe Boating
Before setting out:
Obtain the latest available weather forecast for your boating
area. Where they can be received,the NOAA Weather Radio
continuous broadcasts (VHF-FM) are the best way to keep informed
of expected weather and sea conditions.
If you hear on the radio that marine warnings are in effect, do
not venture out on the water unless you are confident that your
boat can be navigated safely under forecast wind and sea
conditions.
While afloat, stay alert:
1. Keep an eye out for: the approach of dark threatening clouds,
which may foretell a squall or thunderstorm; any steady increase
in wind or sea; any developing decrease in visibility
such as from fog; any increase in wind velocity opposite in
direction to strong tidal current.
A dangerous rip tide condition may form steep waves capable of
broaching a boat.
2. Check radio weather broadcasts for latest forecasts and
warnings.
3. Heavy static on your AM radio may be an indication of nearby
thunderstorm activity.
4. If a thunderstorm catches you while afloat, you should
remember that not only gusty winds but also lightning poses a
threat to safety.
* Stay below deck if possible.
* Keep away from metal objects that are not grounded to the
boat's protection system.
* Do not touch more than one grounded object at the same time (or
you may become a
shortcut for electrical surges passing through the protection
system.)
* Put on a life jacket and prepare for rough seas.
FUTURE MARINE WEATHER SERVICES
New technologies will provide opportunities for improvements in
marine weather services during the next few years. The NWS has
begun a nationwide modernization and restructuring program that
will benefit the marine community. For example, the coastal
weather radar network will be expanded and upgraded with a new
Doppler radar system for improved detection and warning of marine
severe weather. Other observation and data processing systems are
being designed and developed to provide additional improvements
in information timeliness and reliability. The major impact for
mariners will be in the adjustment of marine warning and forecast
areas to take the fullest advantage of these new technologies.
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